Oshaniwa is believed to be heading to Tynecastle on a three-year contract having received a work permit.
The 24-year-old, who represented his country at the 2014 World Cup, is a free agent after leaving Israeli club FC Ashdod. He can play at both centre back and left back.
Oshaniwa told the AfricanFootball.com website: “I am very happy with the development. Going to play in Scotland is a good move for me.
“The profession is about movement and I am looking forward to joining the team and moving to a bigger level. It’s a sign of better days ahead for me.”
Oshaniwa would become the Tynecastle club’s fourth signing of the summer, joining Gavin Reilly, Juanma Delgado and fellow defender Blazej Augustyn.